***

title: refer
slug: /reference/python/rest/calling/refer
description: Send a SIP REFER to transfer a call at the SIP level via REST.
max-toc-depth: 3
---------------------

For a complete index of all SignalWire documentation pages, fetch https://signalwire.com/docs/llms.txt

[transfer]: /docs/server-sdks/reference/python/rest/calling/transfer

Send a SIP REFER on an active call. This initiates a SIP-level transfer,
asking the remote endpoint to connect to a new destination. Unlike
[`transfer()`][transfer], which is
handled by SignalWire, a SIP REFER delegates the transfer to the remote
SIP endpoint.

<Note>
  SIP REFER is only applicable to SIP calls. It will not work on PSTN calls.
</Note>

<EndpointSchemaSnippet endpoint="POST /api/calling/calls" />

## **Response Example**

<EndpointResponseSnippet endpoint="POST /api/calling/calls" />

## **Example**

```python {9}
from signalwire.rest import RestClient

client = RestClient(
    project="your-project-id",
    token="your-api-token",
    host="your-space.signalwire.com",
)

client.calling.refer(
    call_id="call-id-xxx",
    device={"type": "sip", "params": {"to": "sip:sales@example.com"}},
)
```